In a condition involving instability and deformation of a spine, for example, spondylosis deformans, scoliosis, and spinal injury, a spinal fixation surgery using a titanium-made implant is widely performed. The spinal fixation surgery is a surgery for inserting or fixing, for example, the titanium-made implant to the spine so as to improve the stability by fixing the spine.
The tools for fixing the spine includes, for example, a device disclosed in Patent Document 1. Patent Document 1 discloses a device to correct the spine for fixation. This device includes a spinal rod, a spinal hook and a bone screw for fixing the spinal rod to a vertebra such as a thoracic spine or a lumbar spine.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2007-307394